Nowadays, quarter window is widely used in automobiles to improve driver's field of vision or make a vehicle aesthetic in appearance. FIG. 1 schematically illustrates a quarter window mounted on a vehicle door. Referring to FIG. 1, a quarter window 1 is fixed to a vehicle doorframe 2. The quarter window 1 includes a quarter window glass 3, an encapsulation 4 surrounding edges of the quarter window glass 3, and a guide rail 6 for guiding a vehicle window glass 5 to move along a direction indicated by an arrow as shown in FIG. 1. The encapsulation 4 includes at least a first encapsulation section 41, a second encapsulation section 42 and a third encapsulation section 43 to match the shape of the quarter window glass 3. The guide rail 6 is connected with the first encapsulation section 41, as such, the guide rail 6 is fixed to the quarter window glass 3. An encapsulated quarter window glass can be assembled directly in a car production line, which thus shortens assembly cycle. In addition, the encapsulated quarter window glass can be tightly connected with a car body, which thus improves sealing performance and appearance.
FIG. 2 schematically illustrates a structural diagram of the guide rail of the quarter window shown in FIG. 1. Referring to FIG. 2, the guide rail 6 includes a first structure 61 that is adapted to be embedded in the vehicle doorframe, and a second structure 62 that is adapted to be disposed outside the vehicle doorframe and fixed to the first structure 61. Generally, the first structure 61 is integrated with the second structure 62 as a whole. The first structure 61 includes a bottom wall 611, a first side wall 612 disposed on a first surface S1 of the bottom wall 611, and a second side wall 613 disposed on the first surface S1. The second side wall 613 is opposite to the first side wall 612, such that a vehicle window glass can move between the first side wall 612 and the second side wall 613. The first structure 61 of the guide rail 6 as a whole thus takes a U shape. The second structure 62 includes a bottom wall 621, and a first side wall 622 on a first surface S2 of the bottom wall 621. An extension part 63 is disposed on a second surface S3 of the bottom wall 621 of the second structure 62. The second surface S3 is opposite to the first surface S2. Referring to FIG. 1, the extension part 63 is connected with the first encapsulation section 41 of the encapsulation 4, as such, the guide rail 6 is fixed to the quarter window glass 3. After the quarter window 1 is mounted on the vehicle doorframe 2, the quarter window glass 3 and the vehicle window glass 5 are mounted on both sides of the guide rail 6, respectively. In some cases, a groove 631 may be provided within the extension part 63. An opening of the groove 631 may be on a surface S4 of the extension part 63.
Referring to FIG. 1 and FIG. 2, the quarter window 1 may be formed as follows. First, an ordinary annealed glass is cut into a required size. Then, molding and toughening are performed on the glass to obtain the quarter window glass 3. Thereafter, the quarter window glass 3 and the guide rail 6 as inserts are put into a first mold and are positioned therein. Then, a second mold is placed on the first mold, as a result, a cavity for forming the encapsulation 4 is formed between the first mold and the second mold. Thereafter, molten plastics is injected into the cavity, the plastics solidifies and tightly encapsulates the edge of the quarter window glass 3 to form the encapsulation 4. A portion of solidified plastics (which is used to form the first encapsulation section 41) is fixedly connected with the extension part 63 of the guide rail 6, so that the guide rail 6 is fixed to the quarter window glass 3. In order to prevent the molten plastics from entering into the groove 631 of the extension part 63 and avoid an undesired glue overflow structure in the groove 631, the second mold should be pressed against the surface S4 of the extension part 63 during forming the encapsulation 4, such that the second mold may cover the opening of the groove 631 to close up it.
Nevertheless, glue overflow structures are often found in the groove of the guide rail of quarter windows formed using the conventional method, which adversely increases the reject rate of quarter windows. The glue overflow structures may be removed manually to decrease the reject rate, however, which will in turn increase workload and extend the production cycle.